Because I was having problems with AI's on my custom build, I ran a few AI's on trunk (for 40 years) to see where they originated from. The following screenshost show issues I saw with your AI:
1a - doesn't repay loan even though it has more than enough money [EDIT: my bad, it does! ]
1b - doesn't sell off trains losing money even though the 'vehicle seller task' was completed
2a - weird pathfinding in the bottom of the screen towards the station
2b - also curious pathfinding, next to that an unconnected station

You probably already know about them but on the other hand it might help you developing your AI Next to that, your AI didn't build that many routes. Maybe the map is hard with hilly terrain and high sea level. [EDIT: money shortage might be a problem too]. I'm not sure which settings I set for your AI.

Hei, bokkie ,
1. Yes it does pay loan, but quickly take it again
1b. Yes, it doesn't handle that problem.
2a.b. Yes pathfinding is still another issue to taken care.
Thanks bokkie, this would really help .

I tried a game with Trans 90829 among other AI's.
It did nothing at all, except building one depot and a truck loading bay at a power plant. According to the debug window it apparently needs moer money. It was 1977, and it could have loaned 200,000 GBP. Yet it payed it all back and does many runs of (only) trying to plan or build things.
See attached save game and screenshots.
OpenTTD 0.7.3
NewGRFs: OpenGFX, better vehicles names, Av8 1.501

The AI also has problem with custom vehicle sets, it will often fail to build any trains with UKRS, or NARS. It still builds routes, it just never buys trains for them. Often it goes haywire after the first route fails to get a train, it builds a new route right next to it between the same industries(sometimes getting up to 6 different routes between the same industries). With £500,000 loan, at 1921 I'd imagine it should be able to buy at least 1 train. I noticed it does buy a locomotive in the depot, then sells it immediately afterwards, and then moves onto the next route(which often is right alongside the one done beforehand). The AI works fine with the default trains, however.

i.e it reports it found locomotive: 7 and wagon 12 when transporting GRVL with the UKRS + UKRS Addon + PBI + PBI Brick Chain. It worked fine with the same cargo with the default trainset + default wagons carry new cargoes grf.

Well, I would say, it doesn't sort cargoes by price only. It choose a Drop off (sort by number of cargo accepted), check which cargo would be accepted , then find a pair. This would make AI to choose Town / Factory over a Power Plant in Temperate climate, etc.

Brumi wrote:Anyway, it's good to see that you're still working on your AI.

I tired your last version which did well except that it did only build airports. Reading your change log I hoped that it should also build ships and tram service? I loaded the generic tram set.

It might have been that the AI though that air was more profitable, so I turned it off in your AI Settings, but then the AI didn't do anything. I saw that your water connector found two towns close to water which were connected to the same body of water but it never built anything.

Is this intended?

I used a mountainous/rough map but with height distribution = medium so there were still plenty of rather flat areas. (sea-level was set to high)